CZTSSe (Cu2ZnSn(S,Se)4) has served as an attractive earth-abundant semiconductor for photovoltaic devices. CZTSSe materials, however, suffer from bulk defects which can negatively affect device properties. For instance, bulk defects can impact open-circuit voltage (Voc). In fact, Voc exhibited by CZTSSe devices is currently the major limiting factor in efficiency.
Therefore, active materials for photovoltaic device which do not suffer from bulk defects would be desirable.